Communication Scheduling for Control Performance in TSN-Based Fog Computing Platforms

In this paper we are interested in real-time control applications that are implemented using Fog Computing Platforms consisting of interconnected heterogeneous Fog Nodes (FNs). Similar to previous research and ongoing standardization efforts, we assume that the communication between FNs is achieved via the IEEE 802.1 Time Sensitive Networking (TSN) standard. We model the control applications as a set of real-time flows, and we assume that the messages are transmitted using scheduled traffic that is using the Gate Control Lists (GCLs) in TSN. Given a network topology and a set of control applications, we are interested to synthesize the GCLs for messages such that the Quality-of-Control (QoC) of control applications is maximized and the deadlines of real-time messages are satisfied. We have proposed a Constraint Programming (CP)-based solution to this problem, and developed an accurate analytical model for QoC, which, together with a metaheuristic search employed in the CP solver can drive the search quickly towards good quality solutions. We have evaluated the proposed strategy on several test cases including realistic test cases and also validate the resulted GCLs on a TSN hardware platform and via simulations in OMNET++.